# Privacy Policy

Last Updated: 2026-03-13

Effective Date: 2026-03-13

This Privacy Policy applies to "Sudoku Master (sudu)" (the "App").

## 1. Information We Collect

1. Account and identity information: The App does not require account registration and does not directly collect personal identifiers such as your name or phone number.

2. Device and usage information: To ensure functionality and stability, the App may access basic system-provided information (such as OS version, device model, app version, language, and region).

3. In-app data: Includes game progress, completion records, statistics, and preferences (such as sound and language selection).

4. iCloud sync data: When you use iCloud sync, related progress and statistics may be synced across your devices through Apple iCloud/CloudKit.

5. Purchase information: Subscription and lifetime purchase transactions are processed by Apple App Store. We do not store your card or payment credentials; we only rely on Apple transaction status to determine entitlements.

6. Feedback information: If you contact us via email, the information you voluntarily provide (such as email address, issue description, and screenshots) is used for support and troubleshooting.

7. Diagnostics and analytics information: To measure active users, understand feature usage, and identify crashes, we may use Google Firebase to collect app launch events, screen views, feature interactions, session information, device identifiers such as a Firebase installation identifier, crash logs, diagnostic logs, and related device information.

## 2. How We Use Information

1. To provide and maintain core features (gameplay, statistics, settings, and entitlements).

2. To process purchases, restore purchases, and verify subscription status.

3. To support cross-device sync (if you enable iCloud).

4. To respond to feedback and improve product quality and stability.

5. To comply with legal obligations.

6. To measure active users, retention, and feature usage so we can improve product design and operations.

7. To collect and analyze crash, exception, and diagnostic information so we can fix issues and improve stability.

## 3. Data Storage and Security

1. Local data: Most gameplay and settings data are stored on your device.

2. Cloud data: iCloud sync data is hosted by Apple iCloud/CloudKit services.

3. Transaction data: Purchase status is based on Apple transaction records.

4. Analytics and crash data: We may use Google Firebase to provide analytics and crash reporting services, and related data may be processed and stored by Google on our behalf.

5. We take reasonable measures to protect data, but no transmission or storage method is absolutely secure.

## 4. Sharing and Disclosure

1. We do not sell your personal information.

2. We do not share your information with third parties except when:

   - You provide explicit consent;

   - Required by applicable laws or competent authorities;

   - Necessary for payment, subscription verification, and iCloud sync processing by Apple.

   - Necessary for analytics, diagnostics, and crash reporting, processed by Google Firebase as our service provider.

## 5. Your Rights

You may:

1. Delete the App and local data (subject to system behavior after uninstall).

2. Manage or cancel subscriptions in App Store settings.

3. Disable iCloud sync (managed in system iCloud settings).

4. Manage relevant data collection options in system settings or in-app controls if available.

5. Contact us for privacy-related requests.

## 6. Children's Privacy

If you are a minor, please use the App with consent and guidance from your parent or legal guardian.

## 7. Policy Updates

We may update this Policy due to feature changes or legal requirements. The latest version will be displayed in-app.

## 8. Third-Party Services

To support analytics and crash reporting, the App may use the following third-party services:

- Google Firebase Analytics: used to measure active users, session information, and feature usage.

- Google Firebase Crashlytics: used to collect crash logs, exception information, and diagnostic data so we can fix issues.

These third-party services process relevant data according to their applicable terms and rules. We will make reasonable efforts to limit collection to what is necessary for the purposes described above.

## 9. Contact Us

If you have questions about this Policy, contact:

- Email: wangziwei9401@gmaill.com